1. Field of the Invention
This invention generally relates to an image recording system, and more particularly to an image recording material employing a combination of a recording medium and a photoconductor and to an image recording method using the same.
2. Description of the Prior Art
It has been known in the art to record an image on a specific recording medium by use of an electric current passing through the medium from a photoconductor. A variety of such image recording methods have heretofore been invented.
For example, one of such image recording methods is disclosed in U.S. Pat. No. 3,138,547. In the method of this patent, an electrosensitive recording layer which is non-photosensitive is electrically reduced. That is, a dry electrosensitive recording layer comprising a specific metal compound is reduced by an electric current, whereby an image is recorded thereon.
U.S. Pat. No. 3,425,916 discloses an improved method of the method of the above U.S. Pat. No. 3,138,547. In the method of this patent, nuclei constituting a latent image which is capable of being physically developed into a visible image are formed in a recording layer by a relatively small amount of current flow passing through the recording layer from a photoconductor, and then the recording layer containing the nuclei is processed by a developing solution. Thus, the latent image obtained by use of the current flow is developed into a visible image by a physical method.
It is most desirable that the latent image be formed on the recording layer by a relatively small amount of current flowing therethrough in an imagewise pattern, and then the latent image obtained be developed into a visible image by means of a dry process. Such a method is disclosed in Japanese Patent Public Disclosure No. 63,621/1976. In the method of this invention, a latent image is formed on a recording layer comprising a reducible metal compound such as an organic silver, a reducing agent and a binder by use of a current passing through the recording layer in an imagewise pattern, and the the recording layer is uniformly heated. Thus, the latent image is developed into a visible image.
However, since the above-mentioned recording layer is substantially an insulator, the method disclosed in Japanese Patent Public Disclosure No. 63,621/1976 has a defect in that a high voltage of several kilovolts must be impressed to cause a current to pass through the recording layer. In particular, when a photosensitive medium to be developed by heat is used as a recording medium, an even higher voltage is required to cause the current to pass through the support base thereof as well.
Japanese Patent Public Disclosure No. 23,635/1978 discloses a recording medium and a recording method using the same which eliminate the above-mentioned defect. The recording medium of this patent is composed of a support base at least one surface of which is electrically conductive and a recording layer provided on the electrically conductive surface of the support base containing at least one compound selected from the group consisting of benzotriazole and derivatives thereof in addition to the components which constitute the recording layer disclosed in said Japanese Patent Public Disclosure No. 63,621/1976. A latent image is formed on the recording layer of the recording medium by use of a current passing through the recording layer, and then the recording layer is heated to develop the latent image into a visible image. The recording medium has an advantage in that a latent image can be formed on the recording layer thereof by a relatively low voltage, and the latent image can be devloped into a visible image only by heating the recording layer.